How does Dermoid Cyst form, and Where ?

Mature cystic teratomas and dermoid cysts are germ cell tumors; and they originate from one or more of the three germ layers that constitute the embryo. Teratomas constitue the subgroup of germ cell tumors, and one of its subgroups is mature cystic teratomas also known as dermoid cysts.

Now please do not say what’s that to me; because it is important with respect to identify from what group cell the dermoid cyst origin, how they develop and how can they be formed.
But in brief, the most important point to know is that dermoid cysts are benign germ cell tumors, and are in a subgroup of teratomas (please visit the section “What is it?” in our website for details). (1)

The word teratoma is derived from the Greek word for “Terrace” that means monster. The term “dermoid cyst” was used in the veterinary literature in 1831 for the fist time by Leblanc, who removed a lesion containing hair and sebaceous material from a horsehead (2).

The term dermoid cyst has been used for a period of more than 100 years; and today, it is known that mature cystic teratomas are extremely well-differentiated cystic tumors containing tissues that belong to each of the three germ layers, and they are also teratomas.

Since it contains each of the three layers that play a role in the formation of the embryo, it can be involved in the creation of all kinds of organs! However, because it is easier to form keratinized tissues, it often contains sebaceous material and hair.


Sebum (Sebaceous Content) in Dermoid Cyst (Mature Cystic Teratoma)

Sebum (Sebaceous Content) in Dermoid Cyst (Mature Cystic Teratoma)


Bone, hair, and cartilage in 20 cm dermoid cyst (mature cystic teratoma)

Bone, hair, and cartilage in 20 cm dermoid cyst (mature cystic teratoma)


And the question of the century is; How an overian dermoid cyst develop? For example, dermoid cysts can be detected in a 40 day-old baby or 6-year-old child, whereas it can also be detected in a 65-year-old woman. Even though tissues that it contains are interesting, basically the attention-grabbing thing is that ovarian dermoid cysts appear at such a wide variety of different ages.

At the point reached today, studies show that ovarian dermoid cysts originate as a result of abnormal meiosis of germinal cells in ovaries (3). The problem is that when and how pathological signals triggering this abnormal cell division emerge are still unknow.

In fact, this subject has long been investigated. For example, Linder et al investigated the genetic background of dermoid cyst in 1975, and showed that the problems emerge as a result of abnormalities only in one germ cell meiosis (4). Nevertheless, they could not find the answer to the “question of the century” that I asked above.

Although our subject is about ovarian dermoid cysts, they are most commonly seen in the sacrum, i.e. coccyx (57%), when the distribution of all dermoid cysts (mature cystic teratomas) seen in our bodies are investigated. It is a serious problem. Only those who have suffered it knows it:-).

Its prevalence in the reproductive organs, i.e. gonads is 29%. Its prevalence is % 4 in the area behind the peritoneum (retroperitoneal), and is % 3 in the cervix. According to the literature, it is seen in the cervix as well; but in fact, I have not witnessed this 🙂 (5,6)


Tooth in Mature Cystic Teratoma (Dermoid Cyst)

Tooth in Mature Cystic Teratoma (Dermoid Cyst)


Dermoid cysts are seen mostly at ages ranging from 20 to 40. But it can be seen at any ages.

2. Comerci JT Jr, Licciardi F, Bergh PA, Gregori C, Breen JL. Mature cystic teratoma: a clinicopathologic evaluation of 517 cases and review of the literature. Obstet Gynecol. 1994 Jul. 84(1):22-8.
3. Sabol M., Car D, Musani V et. al The Hedgehog signaling pathway in ovarian teratoma is stimulated by Sonic Hedgehog which induces internalization of Patched. Int J Oncol. 2012;41(4):1411-1418.
4. Linder D, McCaw BK, Hecht F. Parthenogenic origin of benign ovarian teratomas. N Engl J Med. 1975; 292(2):63-66.
5. Grosfeld JL, Billmire DF. Teratomas in infancy and childhood. Curr Probl Cancer. 1985 Sep. 9(9):1-53.
6. Swamy R, Embleton N, Hale J. Sacrococcygeal teratoma over two decades: birth prevalence, prenatal diagnosis and clinical outcomes. Prenat Diagn. 2008: 28(11):1048-51.